As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OF FLIGHT 7643 CREWED RECEIVED A FLAP SYSTEM FAILURE MESSAGE AT 8 DEGREES. CREW RETURNED TO YUL, FLIGHT LANDED UNEVENTFULLY, AND PASSENGERS DEPLANED NORMALLY. THE NR 5 FLEX DRIVE SHAFT WAS FOUND FAULTY AND REPLACED. A SATISFACTORY OPERATIONAL CHECK WAS PERFORMED AND AIRCRAFT WAS RELEASED FOR CONTINUED SERVICE.